Tipdog,
The only thing I can think of is to adjust the bars so they are tilted back towards you. You may gain some inches there, but I am puzzled as to why you are having problems going downhill. I weigh 240 pounds and I am only 5'6", I do realize you have 85 pounds more weight then me but with the Grizzly engine braking along with a low range capability, you should be able to crawl down hills.
The only thing I can think of is to adjust the bars so they are tilted back towards you. You may gain some inches there, but I am puzzled as to why you are having problems going downhill. I weigh 240 pounds and I am only 5'6", I do realize you have 85 pounds more weight then me but with the Grizzly engine braking along with a low range capability, you should be able to crawl down hills.